1. Field of Invention
The present invention relates to a multicast group transmission method and a wireless network apparatus using the same, and more particularly to a dynamic multicast group transmission method with queue switching functions and a wireless network apparatus using the same.
2. Related Art
Recently, users surfing internet via wireless network are increasing day by day, such that the consumption of network bandwidth and the demand for network addresses are increasing as well. To solve the problems, the wireless network service providers and the wireless network equipment manufacturers propose a concept of multicast group through which the consumption of network bandwidth can be reduced.
Internet Group Management Protocol (IGMP) is a protocol for managing the multicast group. A node can send a host membership report message to a router, so as to create or join a multicast group in the router. When the router receives a multicast packet, such as a packet carried with multimedia information, destined to the multicast group, the multicast packet is transmitted to each node which is included in the multicast group.
In addition, when the nodes registered in the multicast group, for example wireless devices, enters into the power saving mode due to a power-saving mode being enabled for saving power or other reasons, the nodes are marked during power save mode or standby mode in the multicast group. However, according to IEEE802.11 standard, if a wireless device is unable to receive the media information transmitted by a router due to entering power-saving mode, the packet carried with media information to be transmitted from the router to all nodes registered in the multicast group must be temporarily saved until the wireless device returns to working mode. The packet will be again transmitted to the wireless device once the mark is removed from the multicast group.
As above mentioned, in the same multicast group, other wireless devices in which the power-saving mode are disabled or without the power-saving mode will be delayed in receiving media information until the wireless device returns to working mode. Therefore, it may cause a delay of receiving the media information and have an influence of fluency of receiving the media information for those wireless devices.